1 // SPDX-License-Identifier: GPL-2.0
3 * SuperH On-Chip RTC Support
5 * Copyright (C) 2006 - 2009 Paul Mundt
6 * Copyright (C) 2006 Jamie Lenehan
7 * Copyright (C) 2008 Angelo Castello
9 * Based on the old arch/sh/kernel/cpu/rtc.c by:
11 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
12 * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
14 #include <linux/module.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/kernel.h>
17 #include <linux/bcd.h>
18 #include <linux/rtc.h>
19 #include <linux/init.h>
20 #include <linux/platform_device.h>
21 #include <linux/seq_file.h>
22 #include <linux/interrupt.h>
23 #include <linux/spinlock.h>
25 #include <linux/log2.h>
26 #include <linux/clk.h>
27 #include <linux/slab.h>
31 /* Default values for RZ/A RTC */
32 #define rtc_reg_size sizeof(u16)
33 #define RTC_BIT_INVERTED 0 /* no chip bugs */
34 #define RTC_CAP_4_DIGIT_YEAR (1 << 0)
35 #define RTC_DEF_CAPABILITIES RTC_CAP_4_DIGIT_YEAR
38 #define DRV_NAME "sh-rtc"
40 #define RTC_REG(r) ((r) * rtc_reg_size)
42 #define R64CNT RTC_REG(0)
44 #define RSECCNT RTC_REG(1) /* RTC sec */
45 #define RMINCNT RTC_REG(2) /* RTC min */
46 #define RHRCNT RTC_REG(3) /* RTC hour */
47 #define RWKCNT RTC_REG(4) /* RTC week */
48 #define RDAYCNT RTC_REG(5) /* RTC day */
49 #define RMONCNT RTC_REG(6) /* RTC month */
50 #define RYRCNT RTC_REG(7) /* RTC year */
51 #define RSECAR RTC_REG(8) /* ALARM sec */
52 #define RMINAR RTC_REG(9) /* ALARM min */
53 #define RHRAR RTC_REG(10) /* ALARM hour */
54 #define RWKAR RTC_REG(11) /* ALARM week */
55 #define RDAYAR RTC_REG(12) /* ALARM day */
56 #define RMONAR RTC_REG(13) /* ALARM month */
57 #define RCR1 RTC_REG(14) /* Control */
58 #define RCR2 RTC_REG(15) /* Control */
61 * Note on RYRAR and RCR3: Up until this point most of the register
62 * definitions are consistent across all of the available parts. However,
63 * the placement of the optional RYRAR and RCR3 (the RYRAR control
64 * register used to control RYRCNT/RYRAR compare) varies considerably
65 * across various parts, occasionally being mapped in to a completely
66 * unrelated address space. For proper RYRAR support a separate resource
67 * would have to be handed off, but as this is purely optional in
68 * practice, we simply opt not to support it, thereby keeping the code
69 * quite a bit more simplified.
72 /* ALARM Bits - or with BCD encoded value */
73 #define AR_ENB 0x80 /* Enable for alarm cmp */
76 #define PF_HP 0x100 /* Enable Half Period to support 8,32,128Hz */
77 #define PF_COUNT 0x200 /* Half periodic counter */
78 #define PF_OXS 0x400 /* Periodic One x Second */
79 #define PF_KOU 0x800 /* Kernel or User periodic request 1=kernel */
83 #define RCR1_CF 0x80 /* Carry Flag */
84 #define RCR1_CIE 0x10 /* Carry Interrupt Enable */
85 #define RCR1_AIE 0x08 /* Alarm Interrupt Enable */
86 #define RCR1_AF 0x01 /* Alarm Flag */
89 #define RCR2_PEF 0x80 /* PEriodic interrupt Flag */
90 #define RCR2_PESMASK 0x70 /* Periodic interrupt Set */
91 #define RCR2_RTCEN 0x08 /* ENable RTC */
92 #define RCR2_ADJ 0x04 /* ADJustment (30-second) */
93 #define RCR2_RESET 0x02 /* Reset bit */
94 #define RCR2_START 0x01 /* Start bit */
97 void __iomem
*regbase
;
98 unsigned long regsize
;
104 struct rtc_device
*rtc_dev
;
106 unsigned long capabilities
; /* See asm/rtc.h for cap bits */
107 unsigned short periodic_freq
;
110 static int __sh_rtc_interrupt(struct sh_rtc
*rtc
)
112 unsigned int tmp
, pending
;
114 tmp
= readb(rtc
->regbase
+ RCR1
);
115 pending
= tmp
& RCR1_CF
;
117 writeb(tmp
, rtc
->regbase
+ RCR1
);
119 /* Users have requested One x Second IRQ */
120 if (pending
&& rtc
->periodic_freq
& PF_OXS
)
121 rtc_update_irq(rtc
->rtc_dev
, 1, RTC_UF
| RTC_IRQF
);
126 static int __sh_rtc_alarm(struct sh_rtc
*rtc
)
128 unsigned int tmp
, pending
;
130 tmp
= readb(rtc
->regbase
+ RCR1
);
131 pending
= tmp
& RCR1_AF
;
132 tmp
&= ~(RCR1_AF
| RCR1_AIE
);
133 writeb(tmp
, rtc
->regbase
+ RCR1
);
136 rtc_update_irq(rtc
->rtc_dev
, 1, RTC_AF
| RTC_IRQF
);
141 static int __sh_rtc_periodic(struct sh_rtc
*rtc
)
143 unsigned int tmp
, pending
;
145 tmp
= readb(rtc
->regbase
+ RCR2
);
146 pending
= tmp
& RCR2_PEF
;
148 writeb(tmp
, rtc
->regbase
+ RCR2
);
153 /* Half period enabled than one skipped and the next notified */
154 if ((rtc
->periodic_freq
& PF_HP
) && (rtc
->periodic_freq
& PF_COUNT
))
155 rtc
->periodic_freq
&= ~PF_COUNT
;
157 if (rtc
->periodic_freq
& PF_HP
)
158 rtc
->periodic_freq
|= PF_COUNT
;
159 rtc_update_irq(rtc
->rtc_dev
, 1, RTC_PF
| RTC_IRQF
);
165 static irqreturn_t
sh_rtc_interrupt(int irq
, void *dev_id
)
167 struct sh_rtc
*rtc
= dev_id
;
170 spin_lock(&rtc
->lock
);
171 ret
= __sh_rtc_interrupt(rtc
);
172 spin_unlock(&rtc
->lock
);
174 return IRQ_RETVAL(ret
);
177 static irqreturn_t
sh_rtc_alarm(int irq
, void *dev_id
)
179 struct sh_rtc
*rtc
= dev_id
;
182 spin_lock(&rtc
->lock
);
183 ret
= __sh_rtc_alarm(rtc
);
184 spin_unlock(&rtc
->lock
);
186 return IRQ_RETVAL(ret
);
189 static irqreturn_t
sh_rtc_periodic(int irq
, void *dev_id
)
191 struct sh_rtc
*rtc
= dev_id
;
194 spin_lock(&rtc
->lock
);
195 ret
= __sh_rtc_periodic(rtc
);
196 spin_unlock(&rtc
->lock
);
198 return IRQ_RETVAL(ret
);
201 static irqreturn_t
sh_rtc_shared(int irq
, void *dev_id
)
203 struct sh_rtc
*rtc
= dev_id
;
206 spin_lock(&rtc
->lock
);
207 ret
= __sh_rtc_interrupt(rtc
);
208 ret
|= __sh_rtc_alarm(rtc
);
209 ret
|= __sh_rtc_periodic(rtc
);
210 spin_unlock(&rtc
->lock
);
212 return IRQ_RETVAL(ret
);
215 static inline void sh_rtc_setaie(struct device
*dev
, unsigned int enable
)
217 struct sh_rtc
*rtc
= dev_get_drvdata(dev
);
220 spin_lock_irq(&rtc
->lock
);
222 tmp
= readb(rtc
->regbase
+ RCR1
);
229 writeb(tmp
, rtc
->regbase
+ RCR1
);
231 spin_unlock_irq(&rtc
->lock
);
234 static int sh_rtc_proc(struct device
*dev
, struct seq_file
*seq
)
236 struct sh_rtc
*rtc
= dev_get_drvdata(dev
);
239 tmp
= readb(rtc
->regbase
+ RCR1
);
240 seq_printf(seq
, "carry_IRQ\t: %s\n", (tmp
& RCR1_CIE
) ? "yes" : "no");
242 tmp
= readb(rtc
->regbase
+ RCR2
);
243 seq_printf(seq
, "periodic_IRQ\t: %s\n",
244 (tmp
& RCR2_PESMASK
) ? "yes" : "no");
249 static inline void sh_rtc_setcie(struct device
*dev
, unsigned int enable
)
251 struct sh_rtc
*rtc
= dev_get_drvdata(dev
);
254 spin_lock_irq(&rtc
->lock
);
256 tmp
= readb(rtc
->regbase
+ RCR1
);
263 writeb(tmp
, rtc
->regbase
+ RCR1
);
265 spin_unlock_irq(&rtc
->lock
);
268 static int sh_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
270 sh_rtc_setaie(dev
, enabled
);
274 static int sh_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
276 struct sh_rtc
*rtc
= dev_get_drvdata(dev
);
277 unsigned int sec128
, sec2
, yr
, yr100
, cf_bit
;
279 if (!(readb(rtc
->regbase
+ RCR2
) & RCR2_RTCEN
))
285 spin_lock_irq(&rtc
->lock
);
287 tmp
= readb(rtc
->regbase
+ RCR1
);
288 tmp
&= ~RCR1_CF
; /* Clear CF-bit */
290 writeb(tmp
, rtc
->regbase
+ RCR1
);
292 sec128
= readb(rtc
->regbase
+ R64CNT
);
294 tm
->tm_sec
= bcd2bin(readb(rtc
->regbase
+ RSECCNT
));
295 tm
->tm_min
= bcd2bin(readb(rtc
->regbase
+ RMINCNT
));
296 tm
->tm_hour
= bcd2bin(readb(rtc
->regbase
+ RHRCNT
));
297 tm
->tm_wday
= bcd2bin(readb(rtc
->regbase
+ RWKCNT
));
298 tm
->tm_mday
= bcd2bin(readb(rtc
->regbase
+ RDAYCNT
));
299 tm
->tm_mon
= bcd2bin(readb(rtc
->regbase
+ RMONCNT
)) - 1;
301 if (rtc
->capabilities
& RTC_CAP_4_DIGIT_YEAR
) {
302 yr
= readw(rtc
->regbase
+ RYRCNT
);
303 yr100
= bcd2bin(yr
>> 8);
306 yr
= readb(rtc
->regbase
+ RYRCNT
);
307 yr100
= bcd2bin((yr
== 0x99) ? 0x19 : 0x20);
310 tm
->tm_year
= (yr100
* 100 + bcd2bin(yr
)) - 1900;
312 sec2
= readb(rtc
->regbase
+ R64CNT
);
313 cf_bit
= readb(rtc
->regbase
+ RCR1
) & RCR1_CF
;
315 spin_unlock_irq(&rtc
->lock
);
316 } while (cf_bit
!= 0 || ((sec128
^ sec2
) & RTC_BIT_INVERTED
) != 0);
318 #if RTC_BIT_INVERTED != 0
319 if ((sec128
& RTC_BIT_INVERTED
))
323 /* only keep the carry interrupt enabled if UIE is on */
324 if (!(rtc
->periodic_freq
& PF_OXS
))
325 sh_rtc_setcie(dev
, 0);
327 dev_dbg(dev
, "%s: tm is secs=%d, mins=%d, hours=%d, "
328 "mday=%d, mon=%d, year=%d, wday=%d\n",
330 tm
->tm_sec
, tm
->tm_min
, tm
->tm_hour
,
331 tm
->tm_mday
, tm
->tm_mon
+ 1, tm
->tm_year
, tm
->tm_wday
);
336 static int sh_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
338 struct sh_rtc
*rtc
= dev_get_drvdata(dev
);
342 spin_lock_irq(&rtc
->lock
);
344 /* Reset pre-scaler & stop RTC */
345 tmp
= readb(rtc
->regbase
+ RCR2
);
348 writeb(tmp
, rtc
->regbase
+ RCR2
);
350 writeb(bin2bcd(tm
->tm_sec
), rtc
->regbase
+ RSECCNT
);
351 writeb(bin2bcd(tm
->tm_min
), rtc
->regbase
+ RMINCNT
);
352 writeb(bin2bcd(tm
->tm_hour
), rtc
->regbase
+ RHRCNT
);
353 writeb(bin2bcd(tm
->tm_wday
), rtc
->regbase
+ RWKCNT
);
354 writeb(bin2bcd(tm
->tm_mday
), rtc
->regbase
+ RDAYCNT
);
355 writeb(bin2bcd(tm
->tm_mon
+ 1), rtc
->regbase
+ RMONCNT
);
357 if (rtc
->capabilities
& RTC_CAP_4_DIGIT_YEAR
) {
358 year
= (bin2bcd((tm
->tm_year
+ 1900) / 100) << 8) |
359 bin2bcd(tm
->tm_year
% 100);
360 writew(year
, rtc
->regbase
+ RYRCNT
);
362 year
= tm
->tm_year
% 100;
363 writeb(bin2bcd(year
), rtc
->regbase
+ RYRCNT
);
367 tmp
= readb(rtc
->regbase
+ RCR2
);
369 tmp
|= RCR2_RTCEN
| RCR2_START
;
370 writeb(tmp
, rtc
->regbase
+ RCR2
);
372 spin_unlock_irq(&rtc
->lock
);
377 static inline int sh_rtc_read_alarm_value(struct sh_rtc
*rtc
, int reg_off
)
380 int value
= -1; /* return -1 for ignored values */
382 byte
= readb(rtc
->regbase
+ reg_off
);
384 byte
&= ~AR_ENB
; /* strip the enable bit */
385 value
= bcd2bin(byte
);
391 static int sh_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*wkalrm
)
393 struct sh_rtc
*rtc
= dev_get_drvdata(dev
);
394 struct rtc_time
*tm
= &wkalrm
->time
;
396 spin_lock_irq(&rtc
->lock
);
398 tm
->tm_sec
= sh_rtc_read_alarm_value(rtc
, RSECAR
);
399 tm
->tm_min
= sh_rtc_read_alarm_value(rtc
, RMINAR
);
400 tm
->tm_hour
= sh_rtc_read_alarm_value(rtc
, RHRAR
);
401 tm
->tm_wday
= sh_rtc_read_alarm_value(rtc
, RWKAR
);
402 tm
->tm_mday
= sh_rtc_read_alarm_value(rtc
, RDAYAR
);
403 tm
->tm_mon
= sh_rtc_read_alarm_value(rtc
, RMONAR
);
405 tm
->tm_mon
-= 1; /* RTC is 1-12, tm_mon is 0-11 */
407 wkalrm
->enabled
= (readb(rtc
->regbase
+ RCR1
) & RCR1_AIE
) ? 1 : 0;
409 spin_unlock_irq(&rtc
->lock
);
414 static inline void sh_rtc_write_alarm_value(struct sh_rtc
*rtc
,
415 int value
, int reg_off
)
417 /* < 0 for a value that is ignored */
419 writeb(0, rtc
->regbase
+ reg_off
);
421 writeb(bin2bcd(value
) | AR_ENB
, rtc
->regbase
+ reg_off
);
424 static int sh_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*wkalrm
)
426 struct sh_rtc
*rtc
= dev_get_drvdata(dev
);
428 struct rtc_time
*tm
= &wkalrm
->time
;
431 spin_lock_irq(&rtc
->lock
);
433 /* disable alarm interrupt and clear the alarm flag */
434 rcr1
= readb(rtc
->regbase
+ RCR1
);
435 rcr1
&= ~(RCR1_AF
| RCR1_AIE
);
436 writeb(rcr1
, rtc
->regbase
+ RCR1
);
439 sh_rtc_write_alarm_value(rtc
, tm
->tm_sec
, RSECAR
);
440 sh_rtc_write_alarm_value(rtc
, tm
->tm_min
, RMINAR
);
441 sh_rtc_write_alarm_value(rtc
, tm
->tm_hour
, RHRAR
);
442 sh_rtc_write_alarm_value(rtc
, tm
->tm_wday
, RWKAR
);
443 sh_rtc_write_alarm_value(rtc
, tm
->tm_mday
, RDAYAR
);
447 sh_rtc_write_alarm_value(rtc
, mon
, RMONAR
);
449 if (wkalrm
->enabled
) {
451 writeb(rcr1
, rtc
->regbase
+ RCR1
);
454 spin_unlock_irq(&rtc
->lock
);
459 static const struct rtc_class_ops sh_rtc_ops
= {
460 .read_time
= sh_rtc_read_time
,
461 .set_time
= sh_rtc_set_time
,
462 .read_alarm
= sh_rtc_read_alarm
,
463 .set_alarm
= sh_rtc_set_alarm
,
465 .alarm_irq_enable
= sh_rtc_alarm_irq_enable
,
468 static int __init
sh_rtc_probe(struct platform_device
*pdev
)
471 struct resource
*res
;
475 rtc
= devm_kzalloc(&pdev
->dev
, sizeof(*rtc
), GFP_KERNEL
);
479 spin_lock_init(&rtc
->lock
);
481 /* get periodic/carry/alarm irqs */
482 ret
= platform_get_irq(pdev
, 0);
483 if (unlikely(ret
<= 0)) {
484 dev_err(&pdev
->dev
, "No IRQ resource\n");
488 rtc
->periodic_irq
= ret
;
489 rtc
->carry_irq
= platform_get_irq(pdev
, 1);
490 rtc
->alarm_irq
= platform_get_irq(pdev
, 2);
492 res
= platform_get_resource(pdev
, IORESOURCE_IO
, 0);
494 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
495 if (unlikely(res
== NULL
)) {
496 dev_err(&pdev
->dev
, "No IO resource\n");
500 rtc
->regsize
= resource_size(res
);
502 rtc
->res
= devm_request_mem_region(&pdev
->dev
, res
->start
,
503 rtc
->regsize
, pdev
->name
);
504 if (unlikely(!rtc
->res
))
507 rtc
->regbase
= devm_ioremap(&pdev
->dev
, rtc
->res
->start
, rtc
->regsize
);
508 if (unlikely(!rtc
->regbase
))
511 if (!pdev
->dev
.of_node
) {
513 /* With a single device, the clock id is still "rtc0" */
517 snprintf(clk_name
, sizeof(clk_name
), "rtc%d", clk_id
);
519 snprintf(clk_name
, sizeof(clk_name
), "fck");
521 rtc
->clk
= devm_clk_get(&pdev
->dev
, clk_name
);
522 if (IS_ERR(rtc
->clk
)) {
524 * No error handling for rtc->clk intentionally, not all
525 * platforms will have a unique clock for the RTC, and
526 * the clk API can handle the struct clk pointer being
532 rtc
->rtc_dev
= devm_rtc_allocate_device(&pdev
->dev
);
533 if (IS_ERR(rtc
->rtc_dev
))
534 return PTR_ERR(rtc
->rtc_dev
);
536 clk_enable(rtc
->clk
);
538 rtc
->capabilities
= RTC_DEF_CAPABILITIES
;
541 if (dev_get_platdata(&pdev
->dev
)) {
542 struct sh_rtc_platform_info
*pinfo
=
543 dev_get_platdata(&pdev
->dev
);
546 * Some CPUs have special capabilities in addition to the
547 * default set. Add those in here.
549 rtc
->capabilities
|= pinfo
->capabilities
;
553 if (rtc
->carry_irq
<= 0) {
554 /* register shared periodic/carry/alarm irq */
555 ret
= devm_request_irq(&pdev
->dev
, rtc
->periodic_irq
,
556 sh_rtc_shared
, 0, "sh-rtc", rtc
);
559 "request IRQ failed with %d, IRQ %d\n", ret
,
564 /* register periodic/carry/alarm irqs */
565 ret
= devm_request_irq(&pdev
->dev
, rtc
->periodic_irq
,
566 sh_rtc_periodic
, 0, "sh-rtc period", rtc
);
569 "request period IRQ failed with %d, IRQ %d\n",
570 ret
, rtc
->periodic_irq
);
574 ret
= devm_request_irq(&pdev
->dev
, rtc
->carry_irq
,
575 sh_rtc_interrupt
, 0, "sh-rtc carry", rtc
);
578 "request carry IRQ failed with %d, IRQ %d\n",
579 ret
, rtc
->carry_irq
);
583 ret
= devm_request_irq(&pdev
->dev
, rtc
->alarm_irq
,
584 sh_rtc_alarm
, 0, "sh-rtc alarm", rtc
);
587 "request alarm IRQ failed with %d, IRQ %d\n",
588 ret
, rtc
->alarm_irq
);
593 platform_set_drvdata(pdev
, rtc
);
595 /* everything disabled by default */
596 sh_rtc_setaie(&pdev
->dev
, 0);
597 sh_rtc_setcie(&pdev
->dev
, 0);
599 rtc
->rtc_dev
->ops
= &sh_rtc_ops
;
600 rtc
->rtc_dev
->max_user_freq
= 256;
602 if (rtc
->capabilities
& RTC_CAP_4_DIGIT_YEAR
) {
603 rtc
->rtc_dev
->range_min
= RTC_TIMESTAMP_BEGIN_1900
;
604 rtc
->rtc_dev
->range_max
= RTC_TIMESTAMP_END_9999
;
606 rtc
->rtc_dev
->range_min
= mktime64(1999, 1, 1, 0, 0, 0);
607 rtc
->rtc_dev
->range_max
= mktime64(2098, 12, 31, 23, 59, 59);
610 ret
= rtc_register_device(rtc
->rtc_dev
);
614 device_init_wakeup(&pdev
->dev
, 1);
618 clk_disable(rtc
->clk
);
623 static int __exit
sh_rtc_remove(struct platform_device
*pdev
)
625 struct sh_rtc
*rtc
= platform_get_drvdata(pdev
);
627 sh_rtc_setaie(&pdev
->dev
, 0);
628 sh_rtc_setcie(&pdev
->dev
, 0);
630 clk_disable(rtc
->clk
);
635 static void sh_rtc_set_irq_wake(struct device
*dev
, int enabled
)
637 struct sh_rtc
*rtc
= dev_get_drvdata(dev
);
639 irq_set_irq_wake(rtc
->periodic_irq
, enabled
);
641 if (rtc
->carry_irq
> 0) {
642 irq_set_irq_wake(rtc
->carry_irq
, enabled
);
643 irq_set_irq_wake(rtc
->alarm_irq
, enabled
);
647 static int __maybe_unused
sh_rtc_suspend(struct device
*dev
)
649 if (device_may_wakeup(dev
))
650 sh_rtc_set_irq_wake(dev
, 1);
655 static int __maybe_unused
sh_rtc_resume(struct device
*dev
)
657 if (device_may_wakeup(dev
))
658 sh_rtc_set_irq_wake(dev
, 0);
663 static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops
, sh_rtc_suspend
, sh_rtc_resume
);
665 static const struct of_device_id sh_rtc_of_match
[] = {
666 { .compatible
= "renesas,sh-rtc", },
669 MODULE_DEVICE_TABLE(of
, sh_rtc_of_match
);
671 static struct platform_driver sh_rtc_platform_driver
= {
674 .pm
= &sh_rtc_pm_ops
,
675 .of_match_table
= sh_rtc_of_match
,
677 .remove
= __exit_p(sh_rtc_remove
),
680 module_platform_driver_probe(sh_rtc_platform_driver
, sh_rtc_probe
);
682 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
683 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
684 "Jamie Lenehan <lenehan@twibble.org>, "
685 "Angelo Castello <angelo.castello@st.com>");
686 MODULE_LICENSE("GPL v2");
687 MODULE_ALIAS("platform:" DRV_NAME
);